$(function(){
$(".tab>li").mouseover(function(){
    $(".tab>li").removeClass("on");
	$(this).addClass("on");
    var target = $('#' + this.rel);
    if (target.size() > 0) {
        $('.details > dl').hide();
        target.show();
    } else {
        alert('There is no such container.');
    }
});
});

